Chuck for rock drills



Sept. 8, 1931.

B. F. SH EPHERD CHUCK FOR ROCK DRILLS Filed Aug. 5, 1929 111,5 ATTORNEY.

Patented Sept. 8, 1931 UNITED STATES.

OFFICE BENJAMIN FRANKLIN SHEPHERD, or rnrnnirsnune, NEW JERSEY, AssreNonr INGERSOLL-RAND COMPANY, or JERSEY om'mNEw JERSEY, A conron-ArioN orNEW JERSEY CHUCK FOR ROG! DRILLS This invention relates to rock drills,but

more particularly to chuck mechanism for fluid actuated rock drills ofthe type in which the piston reciprocates independently of the workingimplement for driving the working implement into the work.

the period of usefulness of the chuck mechanism.

Other objects will be in part obvious and in part pointed outhereinafter.

In the drawings accompanying the speciacters refer to similar parts,

Figure 1 is a sectional elevation of the mechanism constructed inaccordance with the practice of the invention, and

through Figure 1 on the lines 2-2 and 33 extends a working implement B,such as a drill steel. trated is of the type commonly referred toopposite sides thereof. The portion D of lugs 0 serves as a shank andextends into the sion E of which is shown.

The rock drill may be provided with suitextension E may interlockslidabl in a well known manner with a chuck nut 4 threaded into therearward end of a chuck G adapted The working implement B illus-,thefront head A and having a cavity Oto receive thel ugs C of theworking implement. vIn the forwardend of the chuck driver L is a bore P.to act as a guidefor the body porl tion of the working implementforwardly of One object of the invention is to prolong 1 pass *wheninserting the working implement into and removing itfrom the fronthead A." In accordance with a .well known practice "the chuckdrijverfLisflprovided .with introfication and in which similar reference char-.verted "-ribs R which extend into the cavity O and aresodisposed withrespect to. the slots :IQ'that after the lugsC are passed through thefront end of a rock drill showing a chuck slots Q ,theworking implementmay be, to tated aJjpartial revolution to carry the lugs Ginto'contactw-ith, the ribs R. I By thus ar- Figures 2 and 3 aretransverse views takeni anging the ribs relatively to the slotsQ, the

front "wall-of the cavity 0 will alsoserve to looking in the directionindicated by the ar-l,

front head. Referring more particularly to the drawings, the inventionis shown embodied in a 25 rock drill having a front head A into whichretain -the wor implement within the -;'Preferably the ribs are somewhatlonger than the lugs 0 so {that the working implement B will be capableof a limited degree" of reciprocationwithin the elements acting asjaguide therefor; Due to this action of 5 the working implement, however,the hardas a Leyner steel and accordingly has a pair of lateral lugs Cdisposed on diametrically" "ened surfaces S of the ribs R against whichthe lugs C bear are subjected tosevcre wear caused by theabrading actionof the lugs C the working implement rearwardly of the against thesesurfaces.

' Although it has been proposed heretofore front head A to receive theblows of a hammer piston, only the forward fluted exten-' lugs of theworking implement, it has been j fo'un'd that when thus treated otheruncleable rotation mechanism, such as a rifle bar (not shown) forimparting rotary movement to the working implement, and the pistontocomplete'ly hardenthe chuck driverto enable it to withstand thewearing action of the soft interior capable of withstanding the strainsimposed upon the chuck the rotationmec'l-ianism.

Thepresent invention contemplates equipdriver by pingthe chuck driverwith means whereby after the case hardened surfaces are worn through,the lugs C of the working implement may continue to bear againstelements riedtibya chuck driver L in the front end of l of at least thesame degree of hardness as the,

case hardened surfaces S so that the chuck? driver may continuerendering useful service for an extended period of time after thehardened surfaces S have been worn away. To this end the chuck driver Lis provided with 5 apertures T in each rib R and preferably adjacent thecase hardened surfaces S but entirely within the soft interior of theribs. Within the apertures T are disposed pins U which may be pressfitted into the apertures T and may be formed of metal possessinginherent hardness or may be suitably hardened to resist the wearingaction of the lugs C.

In practice, when the drill is first placed in service, the lugs O, ofcourse, bear only against the hardened surfaces S; After some usage,however, the hardened surfaces become worn through by the lugs which maythereafter bear directly against the hardened pins U instead of againstthe soft in- 29 terior of the ribs as heretofore. A drill thus equippedwill therefore be capable of being operated for longer periods ofuninterrupted drilling than may those where the ribs are: only providedwith a comparatively thin wear resisting surface.

I claim:

1. In a rock drill, the combination of a front head and a drill steelextending into the front head, lugs on the drill steel, a chuck 30rotatable in the front head and having a cavity to receive the lugs,ribs in the chuck extending into the cavity and having hardened wearresisting surfaces overlying relatively soft interior portions to engagethe lugs, and additional wear resisting means in-- serted in the softinterior portion of the ribs beneath the engaging surfaces andadapted toprevent undue wear of the relatively soft.

interior portions of the ribs by contacting 40 with the lugs on thedrill steel after the hardened surfaces are worn through.

2. In a rock drill, the combination of a front head and a drill steelextending into the front head, lug-s on the drill steel, a chuckrotatable in the front head and having a cavity to receive the lugs,ribs in the chuck extending into the cavity and having hardened wearresisting surfaces overlying relatively soft interior portions to engagethe lugs, and

hardened pins inserted in the soft interior portion of the ribs adjacentthe hardened surfaces and beneath the initial engaging surfaces thereofand adapted to prevent undue wear of the relatively soft interiorportions of the ribs by contacting with the lugs on the drill steelafter the hardened surfaces are worn through.

In testimony whereof I have signed this specification.

B. FRANKLIN SHEPHERD.

